I've had a lot of success with things like this. I'll plop my players into a half-baked campaign setting, often out of necessity (there's only so much that can be done by one person, even over months/years of writing), and as they come up with things about their character that might reflect on a larger reality of the world, I work it in. As they come up with theories about how such-and-such political dynamic works, or what the major exports of such-and-such duchy HAVE to be given my description of it, I (sometimes) work it in. For example, why was one of my player's character named Zook Boddynock Namfudl, when gnomes in this campaign setting all had Scandinavian-inspired names? Turns out there were two types of gnomes (this is 3.5 D&D so that wasn't standard), and she was just not one of the predominant Old Religion gnomes. That explanation seemed fine to me, especially as Zook was a cleric to a human god, so I ended up working in that there was a major division between the (majority) Old Religion gnomes and the (minority) New Religion (i.e., human gods) gnomes. I hadn't developed gnome culture much before this point, so this player-created sectarian divide was a great way of fleshing out their culture.